//========================================================================
// GLFW 3.3 GLX - www.glfw.org
//------------------------------------------------------------------------
// Copyright (c) 2002-2006 Marcus Geelnard
// Copyright (c) 2006-2019 Camilla Löwy <elmindreda@glfw.org>
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
//    claim that you wrote the original software. If you use this software
//    in a product, an acknowledgment in the product documentation would
//    be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not
//    be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source
//    distribution.
//
//========================================================================
// It is fine to use C99 in this file because it will not be built with VS
//========================================================================

#include "internal.h"

#include <string.h>
#include <stdlib.h>
#include <assert.h>

#ifndef GLXBadProfileARB
#define GLXBadProfileARB 13
#endif

// Returns the specified attribute of the specified GLXFBConfig
//
static int getGLXFBConfigAttrib(GLXFBConfig fbconfig, int attrib) {
  int value;
  glXGetFBConfigAttrib(_glfw.x11.display, fbconfig, attrib, &value);
  return value;
}

// Return the GLXFBConfig most closely matching the specified hints
//
static GLFWbool chooseGLXFBConfig(const _GLFWfbconfig* desired,
                                  GLXFBConfig* result) {
  GLXFBConfig* nativeConfigs;
  _GLFWfbconfig* usableConfigs;
  const _GLFWfbconfig* closest;
  int i, nativeCount, usableCount;
  const char* vendor;
  GLFWbool trustWindowBit = GLFW_TRUE;

  // HACK: This is a (hopefully temporary) workaround for Chromium
  //       (VirtualBox GL) not setting the window bit on any GLXFBConfigs
  vendor = glXGetClientString(_glfw.x11.display, GLX_VENDOR);
  if (vendor && strcmp(vendor, "Chromium") == 0)
    trustWindowBit = GLFW_FALSE;

  nativeConfigs =
      glXGetFBConfigs(_glfw.x11.display, _glfw.x11.screen, &nativeCount);
  if (!nativeConfigs || !nativeCount) {
    _glfwInputError(GLFW_API_UNAVAILABLE, "GLX: No GLXFBConfigs returned");
    return GLFW_FALSE;
  }

  usableConfigs = calloc(nativeCount, sizeof(_GLFWfbconfig));
  usableCount = 0;

  for (i = 0; i < nativeCount; i++) {
    const GLXFBConfig n = nativeConfigs[i];
    _GLFWfbconfig* u = usableConfigs + usableCount;

    // Only consider RGBA GLXFBConfigs
    if (!(getGLXFBConfigAttrib(n, GLX_RENDER_TYPE) & GLX_RGBA_BIT))
      continue;

    // Only consider window GLXFBConfigs
    if (!(getGLXFBConfigAttrib(n, GLX_DRAWABLE_TYPE) & GLX_WINDOW_BIT)) {
      if (trustWindowBit)
        continue;
    }

    if (getGLXFBConfigAttrib(n, GLX_DOUBLEBUFFER) != desired->doublebuffer)
      continue;

    if (desired->transparent) {
      XVisualInfo* vi = glXGetVisualFromFBConfig(_glfw.x11.display, n);
      if (vi) {
        u->transparent = _glfwIsVisualTransparentX11(vi->visual);
        XFree(vi);
      }
    }

    u->redBits = getGLXFBConfigAttrib(n, GLX_RED_SIZE);
    u->greenBits = getGLXFBConfigAttrib(n, GLX_GREEN_SIZE);
    u->blueBits = getGLXFBConfigAttrib(n, GLX_BLUE_SIZE);

    u->alphaBits = getGLXFBConfigAttrib(n, GLX_ALPHA_SIZE);
    u->depthBits = getGLXFBConfigAttrib(n, GLX_DEPTH_SIZE);
    u->stencilBits = getGLXFBConfigAttrib(n, GLX_STENCIL_SIZE);

    u->accumRedBits = getGLXFBConfigAttrib(n, GLX_ACCUM_RED_SIZE);
    u->accumGreenBits = getGLXFBConfigAttrib(n, GLX_ACCUM_GREEN_SIZE);
    u->accumBlueBits = getGLXFBConfigAttrib(n, GLX_ACCUM_BLUE_SIZE);
    u->accumAlphaBits = getGLXFBConfigAttrib(n, GLX_ACCUM_ALPHA_SIZE);

    u->auxBuffers = getGLXFBConfigAttrib(n, GLX_AUX_BUFFERS);

    if (getGLXFBConfigAttrib(n, GLX_STEREO))
      u->stereo = GLFW_TRUE;

    if (_glfw.glx.ARB_multisample)
      u->samples = getGLXFBConfigAttrib(n, GLX_SAMPLES);

    if (_glfw.glx.ARB_framebuffer_sRGB || _glfw.glx.EXT_framebuffer_sRGB)
      u->sRGB = getGLXFBConfigAttrib(n, GLX_FRAMEBUFFER_SRGB_CAPABLE_ARB);

    u->handle = (uintptr_t)n;
    usableCount++;
  }

  closest = _glfwChooseFBConfig(desired, usableConfigs, usableCount);
  if (closest)
    *result = (GLXFBConfig)closest->handle;

  XFree(nativeConfigs);
  free(usableConfigs);

  return closest != NULL;
}

// Create the OpenGL context using legacy API
//
static GLXContext createLegacyContextGLX(_GLFWwindow* window,
                                         GLXFBConfig fbconfig,
                                         GLXContext share) {
  return glXCreateNewContext(_glfw.x11.display,
                             fbconfig,
                             GLX_RGBA_TYPE,
                             share,
                             True);
}

static void makeContextCurrentGLX(_GLFWwindow* window) {
  if (window) {
    if (!glXMakeCurrent(_glfw.x11.display,
                        window->context.glx.window,
                        window->context.glx.handle)) {
      _glfwInputError(GLFW_PLATFORM_ERROR,
                      "GLX: Failed to make context current");
      return;
    }
  } else {
    if (!glXMakeCurrent(_glfw.x11.display, None, NULL)) {
      _glfwInputError(GLFW_PLATFORM_ERROR,
                      "GLX: Failed to clear current context");
      return;
    }
  }

  _glfwPlatformSetTls(&_glfw.contextSlot, window);
}

static void swapBuffersGLX(_GLFWwindow* window) {
  glXSwapBuffers(_glfw.x11.display, window->context.glx.window);
}

static void swapIntervalGLX(int interval) {
  _GLFWwindow* window = _glfwPlatformGetTls(&_glfw.contextSlot);

  if (_glfw.glx.EXT_swap_control) {
    _glfw.glx.SwapIntervalEXT(_glfw.x11.display,
                              window->context.glx.window,
                              interval);
  } else if (_glfw.glx.MESA_swap_control)
    _glfw.glx.SwapIntervalMESA(interval);
  else if (_glfw.glx.SGI_swap_control) {
    if (interval > 0)
      _glfw.glx.SwapIntervalSGI(interval);
  }
}

static int extensionSupportedGLX(const char* extension) {
  const char* extensions =
      glXQueryExtensionsString(_glfw.x11.display, _glfw.x11.screen);
  if (extensions) {
    if (_glfwStringInExtensionString(extension, extensions))
      return GLFW_TRUE;
  }

  return GLFW_FALSE;
}

static GLFWglproc getProcAddressGLX(const char* procname) {
  if (_glfw.glx.GetProcAddress)
    return _glfw.glx.GetProcAddress((const GLubyte*)procname);
  else if (_glfw.glx.GetProcAddressARB)
    return _glfw.glx.GetProcAddressARB((const GLubyte*)procname);
  else
    return _glfw_dlsym(_glfw.glx.handle, procname);
}

static void destroyContextGLX(_GLFWwindow* window) {
  if (window->context.glx.window) {
    glXDestroyWindow(_glfw.x11.display, window->context.glx.window);
    window->context.glx.window = None;
  }

  if (window->context.glx.handle) {
    glXDestroyContext(_glfw.x11.display, window->context.glx.handle);
    window->context.glx.handle = NULL;
  }
}

//////////////////////////////////////////////////////////////////////////
//////                       GLFW internal API                      //////
//////////////////////////////////////////////////////////////////////////

// Initialize GLX
//
GLFWbool _glfwInitGLX(void) {
  int i;
  const char* sonames[] =
  {
#if defined(_GLFW_GLX_LIBRARY)
    _GLFW_GLX_LIBRARY,
#elif defined(__CYGWIN__)
    "libGL-1.so",
#else
    "libGL.so.1",
    "libGL.so",
#endif
    NULL
  };

  if (_glfw.glx.handle)
    return GLFW_TRUE;

  for (i = 0; sonames[i]; i++) {
    _glfw.glx.handle = _glfw_dlopen(sonames[i]);
    if (_glfw.glx.handle)
      break;
  }

  if (!_glfw.glx.handle) {
    _glfwInputError(GLFW_API_UNAVAILABLE, "GLX: Failed to load GLX");
    return GLFW_FALSE;
  }

  _glfw.glx.GetFBConfigs =
      _glfw_dlsym(_glfw.glx.handle, "glXGetFBConfigs");
  _glfw.glx.GetFBConfigAttrib =
      _glfw_dlsym(_glfw.glx.handle, "glXGetFBConfigAttrib");
  _glfw.glx.GetClientString =
      _glfw_dlsym(_glfw.glx.handle, "glXGetClientString");
  _glfw.glx.QueryExtension =
      _glfw_dlsym(_glfw.glx.handle, "glXQueryExtension");
  _glfw.glx.QueryVersion =
      _glfw_dlsym(_glfw.glx.handle, "glXQueryVersion");
  _glfw.glx.DestroyContext =
      _glfw_dlsym(_glfw.glx.handle, "glXDestroyContext");
  _glfw.glx.MakeCurrent =
      _glfw_dlsym(_glfw.glx.handle, "glXMakeCurrent");
  _glfw.glx.SwapBuffers =
      _glfw_dlsym(_glfw.glx.handle, "glXSwapBuffers");
  _glfw.glx.QueryExtensionsString =
      _glfw_dlsym(_glfw.glx.handle, "glXQueryExtensionsString");
  _glfw.glx.CreateNewContext =
      _glfw_dlsym(_glfw.glx.handle, "glXCreateNewContext");
  _glfw.glx.CreateWindow =
      _glfw_dlsym(_glfw.glx.handle, "glXCreateWindow");
  _glfw.glx.DestroyWindow =
      _glfw_dlsym(_glfw.glx.handle, "glXDestroyWindow");
  _glfw.glx.GetProcAddress =
      _glfw_dlsym(_glfw.glx.handle, "glXGetProcAddress");
  _glfw.glx.GetProcAddressARB =
      _glfw_dlsym(_glfw.glx.handle, "glXGetProcAddressARB");
  _glfw.glx.GetVisualFromFBConfig =
      _glfw_dlsym(_glfw.glx.handle, "glXGetVisualFromFBConfig");

  if (!_glfw.glx.GetFBConfigs ||
      !_glfw.glx.GetFBConfigAttrib ||
      !_glfw.glx.GetClientString ||
      !_glfw.glx.QueryExtension ||
      !_glfw.glx.QueryVersion ||
      !_glfw.glx.DestroyContext ||
      !_glfw.glx.MakeCurrent ||
      !_glfw.glx.SwapBuffers ||
      !_glfw.glx.QueryExtensionsString ||
      !_glfw.glx.CreateNewContext ||
      !_glfw.glx.CreateWindow ||
      !_glfw.glx.DestroyWindow ||
      !_glfw.glx.GetProcAddress ||
      !_glfw.glx.GetProcAddressARB ||
      !_glfw.glx.GetVisualFromFBConfig) {
    _glfwInputError(GLFW_PLATFORM_ERROR,
                    "GLX: Failed to load required entry points");
    return GLFW_FALSE;
  }

  if (!glXQueryExtension(_glfw.x11.display,
                         &_glfw.glx.errorBase,
                         &_glfw.glx.eventBase)) {
    _glfwInputError(GLFW_API_UNAVAILABLE, "GLX: GLX extension not found");
    return GLFW_FALSE;
  }

  if (!glXQueryVersion(_glfw.x11.display, &_glfw.glx.major, &_glfw.glx.minor)) {
    _glfwInputError(GLFW_API_UNAVAILABLE,
                    "GLX: Failed to query GLX version");
    return GLFW_FALSE;
  }

  if (_glfw.glx.major == 1 && _glfw.glx.minor < 3) {
    _glfwInputError(GLFW_API_UNAVAILABLE,
                    "GLX: GLX version 1.3 is required");
    return GLFW_FALSE;
  }

  if (extensionSupportedGLX("GLX_EXT_swap_control")) {
    _glfw.glx.SwapIntervalEXT = (PFNGLXSWAPINTERVALEXTPROC)
        getProcAddressGLX("glXSwapIntervalEXT");

    if (_glfw.glx.SwapIntervalEXT)
      _glfw.glx.EXT_swap_control = GLFW_TRUE;
  }

  if (extensionSupportedGLX("GLX_SGI_swap_control")) {
    _glfw.glx.SwapIntervalSGI = (PFNGLXSWAPINTERVALSGIPROC)
        getProcAddressGLX("glXSwapIntervalSGI");

    if (_glfw.glx.SwapIntervalSGI)
      _glfw.glx.SGI_swap_control = GLFW_TRUE;
  }

  if (extensionSupportedGLX("GLX_MESA_swap_control")) {
    _glfw.glx.SwapIntervalMESA = (PFNGLXSWAPINTERVALMESAPROC)
        getProcAddressGLX("glXSwapIntervalMESA");

    if (_glfw.glx.SwapIntervalMESA)
      _glfw.glx.MESA_swap_control = GLFW_TRUE;
  }

  if (extensionSupportedGLX("GLX_ARB_multisample"))
    _glfw.glx.ARB_multisample = GLFW_TRUE;

  if (extensionSupportedGLX("GLX_ARB_framebuffer_sRGB"))
    _glfw.glx.ARB_framebuffer_sRGB = GLFW_TRUE;

  if (extensionSupportedGLX("GLX_EXT_framebuffer_sRGB"))
    _glfw.glx.EXT_framebuffer_sRGB = GLFW_TRUE;

  if (extensionSupportedGLX("GLX_ARB_create_context")) {
    _glfw.glx.CreateContextAttribsARB = (PFNGLXCREATECONTEXTATTRIBSARBPROC)
        getProcAddressGLX("glXCreateContextAttribsARB");

    if (_glfw.glx.CreateContextAttribsARB)
      _glfw.glx.ARB_create_context = GLFW_TRUE;
  }

  if (extensionSupportedGLX("GLX_ARB_create_context_robustness"))
    _glfw.glx.ARB_create_context_robustness = GLFW_TRUE;

  if (extensionSupportedGLX("GLX_ARB_create_context_profile"))
    _glfw.glx.ARB_create_context_profile = GLFW_TRUE;

  if (extensionSupportedGLX("GLX_EXT_create_context_es2_profile"))
    _glfw.glx.EXT_create_context_es2_profile = GLFW_TRUE;

  if (extensionSupportedGLX("GLX_ARB_create_context_no_error"))
    _glfw.glx.ARB_create_context_no_error = GLFW_TRUE;

  if (extensionSupportedGLX("GLX_ARB_context_flush_control"))
    _glfw.glx.ARB_context_flush_control = GLFW_TRUE;

  return GLFW_TRUE;
}

// Terminate GLX
//
void _glfwTerminateGLX(void) {
  // NOTE: This function must not call any X11 functions, as it is called
  //       after XCloseDisplay (see _glfwPlatformTerminate for details)

  if (_glfw.glx.handle) {
    _glfw_dlclose(_glfw.glx.handle);
    _glfw.glx.handle = NULL;
  }
}

#define setAttrib(a, v) \
  { \
    assert(((size_t)index + 1) < sizeof(attribs) / sizeof(attribs[0])); \
    attribs[index++] = a; \
    attribs[index++] = v; \
  }

// Create the OpenGL or OpenGL ES context
//
GLFWbool _glfwCreateContextGLX(_GLFWwindow* window,
                               const _GLFWctxconfig* ctxconfig,
                               const _GLFWfbconfig* fbconfig) {
  int attribs[40];
  GLXFBConfig native = NULL;
  GLXContext share = NULL;

  if (ctxconfig->share)
    share = ctxconfig->share->context.glx.handle;

  if (!chooseGLXFBConfig(fbconfig, &native)) {
    _glfwInputError(GLFW_FORMAT_UNAVAILABLE,
                    "GLX: Failed to find a suitable GLXFBConfig");
    return GLFW_FALSE;
  }

  if (ctxconfig->client == GLFW_OPENGL_ES_API) {
    if (!_glfw.glx.ARB_create_context ||
        !_glfw.glx.ARB_create_context_profile ||
        !_glfw.glx.EXT_create_context_es2_profile) {
      _glfwInputError(GLFW_API_UNAVAILABLE,
                      "GLX: OpenGL ES requested but GLX_EXT_create_context_es2_profile is unavailable");
      return GLFW_FALSE;
    }
  }

  if (ctxconfig->forward) {
    if (!_glfw.glx.ARB_create_context) {
      _glfwInputError(GLFW_VERSION_UNAVAILABLE,
                      "GLX: Forward compatibility requested but GLX_ARB_create_context_profile is unavailable");
      return GLFW_FALSE;
    }
  }

  if (ctxconfig->profile) {
    if (!_glfw.glx.ARB_create_context ||
        !_glfw.glx.ARB_create_context_profile) {
      _glfwInputError(GLFW_VERSION_UNAVAILABLE,
                      "GLX: An OpenGL profile requested but GLX_ARB_create_context_profile is unavailable");
      return GLFW_FALSE;
    }
  }

  _glfwGrabErrorHandlerX11();

  if (_glfw.glx.ARB_create_context) {
    int index = 0, mask = 0, flags = 0;

    if (ctxconfig->client == GLFW_OPENGL_API) {
      if (ctxconfig->forward)
        flags |= GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB;

      if (ctxconfig->profile == GLFW_OPENGL_CORE_PROFILE)
        mask |= GLX_CONTEXT_CORE_PROFILE_BIT_ARB;
      else if (ctxconfig->profile == GLFW_OPENGL_COMPAT_PROFILE)
        mask |= GLX_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB;
    } else
      mask |= GLX_CONTEXT_ES2_PROFILE_BIT_EXT;

    if (ctxconfig->debug)
      flags |= GLX_CONTEXT_DEBUG_BIT_ARB;

    if (ctxconfig->robustness) {
      if (_glfw.glx.ARB_create_context_robustness) {
        if (ctxconfig->robustness == GLFW_NO_RESET_NOTIFICATION) {
          setAttrib(GLX_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB,
                    GLX_NO_RESET_NOTIFICATION_ARB);
        } else if (ctxconfig->robustness == GLFW_LOSE_CONTEXT_ON_RESET) {
          setAttrib(GLX_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB,
                    GLX_LOSE_CONTEXT_ON_RESET_ARB);
        }

        flags |= GLX_CONTEXT_ROBUST_ACCESS_BIT_ARB;
      }
    }

    if (ctxconfig->release) {
      if (_glfw.glx.ARB_context_flush_control) {
        if (ctxconfig->release == GLFW_RELEASE_BEHAVIOR_NONE) {
          setAttrib(GLX_CONTEXT_RELEASE_BEHAVIOR_ARB,
                    GLX_CONTEXT_RELEASE_BEHAVIOR_NONE_ARB);
        } else if (ctxconfig->release == GLFW_RELEASE_BEHAVIOR_FLUSH) {
          setAttrib(GLX_CONTEXT_RELEASE_BEHAVIOR_ARB,
                    GLX_CONTEXT_RELEASE_BEHAVIOR_FLUSH_ARB);
        }
      }
    }

    if (ctxconfig->noerror) {
      if (_glfw.glx.ARB_create_context_no_error)
        setAttrib(GLX_CONTEXT_OPENGL_NO_ERROR_ARB, GLFW_TRUE);
    }

    // NOTE: Only request an explicitly versioned context when necessary, as
    //       explicitly requesting version 1.0 does not always return the
    //       highest version supported by the driver
    if (ctxconfig->major != 1 || ctxconfig->minor != 0) {
      setAttrib(GLX_CONTEXT_MAJOR_VERSION_ARB, ctxconfig->major);
      setAttrib(GLX_CONTEXT_MINOR_VERSION_ARB, ctxconfig->minor);
    }

    if (mask)
      setAttrib(GLX_CONTEXT_PROFILE_MASK_ARB, mask);

    if (flags)
      setAttrib(GLX_CONTEXT_FLAGS_ARB, flags);

    setAttrib(None, None);

    window->context.glx.handle =
        _glfw.glx.CreateContextAttribsARB(_glfw.x11.display,
                                          native,
                                          share,
                                          True,
                                          attribs);

    // HACK: This is a fallback for broken versions of the Mesa
    //       implementation of GLX_ARB_create_context_profile that fail
    //       default 1.0 context creation with a GLXBadProfileARB error in
    //       violation of the extension spec
    if (!window->context.glx.handle) {
      if (_glfw.x11.errorCode == _glfw.glx.errorBase + GLXBadProfileARB &&
          ctxconfig->client == GLFW_OPENGL_API &&
          ctxconfig->profile == GLFW_OPENGL_ANY_PROFILE &&
          ctxconfig->forward == GLFW_FALSE) {
        window->context.glx.handle =
            createLegacyContextGLX(window, native, share);
      }
    }
  } else {
    window->context.glx.handle =
        createLegacyContextGLX(window, native, share);
  }

  _glfwReleaseErrorHandlerX11();

  if (!window->context.glx.handle) {
    _glfwInputErrorX11(GLFW_VERSION_UNAVAILABLE, "GLX: Failed to create context");
    return GLFW_FALSE;
  }

  window->context.glx.window =
      glXCreateWindow(_glfw.x11.display, native, window->x11.handle, NULL);
  if (!window->context.glx.window) {
    _glfwInputError(GLFW_PLATFORM_ERROR, "GLX: Failed to create window");
    return GLFW_FALSE;
  }

  window->context.makeCurrent = makeContextCurrentGLX;
  window->context.swapBuffers = swapBuffersGLX;
  window->context.swapInterval = swapIntervalGLX;
  window->context.extensionSupported = extensionSupportedGLX;
  window->context.getProcAddress = getProcAddressGLX;
  window->context.destroy = destroyContextGLX;

  return GLFW_TRUE;
}

#undef setAttrib

// Returns the Visual and depth of the chosen GLXFBConfig
//
GLFWbool _glfwChooseVisualGLX(const _GLFWwndconfig* wndconfig,
                              const _GLFWctxconfig* ctxconfig,
                              const _GLFWfbconfig* fbconfig,
                              Visual** visual, int* depth) {
  GLXFBConfig native;
  XVisualInfo* result;

  if (!chooseGLXFBConfig(fbconfig, &native)) {
    _glfwInputError(GLFW_FORMAT_UNAVAILABLE,
                    "GLX: Failed to find a suitable GLXFBConfig");
    return GLFW_FALSE;
  }

  result = glXGetVisualFromFBConfig(_glfw.x11.display, native);
  if (!result) {
    _glfwInputError(GLFW_PLATFORM_ERROR,
                    "GLX: Failed to retrieve Visual for GLXFBConfig");
    return GLFW_FALSE;
  }

  *visual = result->visual;
  *depth = result->depth;

  XFree(result);
  return GLFW_TRUE;
}

//////////////////////////////////////////////////////////////////////////
//////                        GLFW native API                       //////
//////////////////////////////////////////////////////////////////////////

GLFWAPI GLXContext glfwGetGLXContext(GLFWwindow* handle) {
  _GLFWwindow* window = (_GLFWwindow*)handle;
  _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

  if (window->context.client == GLFW_NO_API) {
    _glfwInputError(GLFW_NO_WINDOW_CONTEXT, NULL);
    return NULL;
  }

  return window->context.glx.handle;
}

GLFWAPI GLXWindow glfwGetGLXWindow(GLFWwindow* handle) {
  _GLFWwindow* window = (_GLFWwindow*)handle;
  _GLFW_REQUIRE_INIT_OR_RETURN(None);

  if (window->context.client == GLFW_NO_API) {
    _glfwInputError(GLFW_NO_WINDOW_CONTEXT, NULL);
    return None;
  }

  return window->context.glx.window;
}
